From upstream to downstream, companies that work with natural gas rely heavily on pipeline infrastructure for the delivery of natural gas from the source to the end user. But what happens when that infrastructure is not in place? Moving large volumes of natural gas via mobile pipeline provides safe and expedient transportation and storage when demand exceeds capacity or is beyond the reach of the conventional pipeline.
Compressed natural gas can be delivered via mobile pipeline solutions that utilize composite cylinders that hold four times more gas and weigh 75 percent less than comparable steel tubes. Specially designed trailers and modules outfitted with the lighter composite cylinders enable gas transporters to carry more gas on each delivery and realize a faster return on investment on their mobile pipeline assets.
A growing number of mobile pipeline applications are meeting a broad range of gas market and consumer needs in the United States and around the world. Resourceful providers are continuously building new delivery paths with economic and environmental benefits. Three increasingly popular applications for utility companies include:
One of the more recently developed uses for mobile pipeline equipment is pipeline injection, also known as virtual interconnect. Certain geographic areas may have inadequate pipeline capacity to meet peak demand requirements for natural gas supply. Furthermore, these same areas may have political roadblocks that are preventing additional pipelines from being constructed to meet peak natural gas demand from consumers and industry. Mobile pipeline is part of the solution to increase natural gas supply to areas that have constrained supply.
Gas islands are another downstream use for mobile pipeline. A gas island typically is represented as a town, an industrial park or another region that is isolated from the natural gas grid. Utility gas service may exist within the gas island, but the delivery method is different. Mobile pipeline for a gas island represents the transmission line to the distribution area via module delivery by truck.
As a biogas that has been cleaned and upgraded to pipeline and utility standards, renewable natural gas introduces new opportunities for the waste and agricultural industries to provide an ultra-clean and ultra-low-carbon natural gas alternative for utilities. RNG represents the leading edge in our fight against climate change, with many sources of RNG certified by the California Air Resources Board having a near-zero or even negative carbon intensity. Mobile pipeline is one method that allows utilities to source this clean fuel for their customers and deliver RNG to the distribution territory.
Successful mobile pipeline projects include important practices such as working with an experienced team to assess regional and seasonal needs, direct and indirect costs, and total cost of ownership. With thousands of mobile pipeline deployments around the world, these practices have been developed to ensure safety and regulatory compliance and produce optimal results. Key best practices include:
Estimate the required volume and loads: CNG can be stored and transported in volumes up to 492,180 standard cubic feet or 13,937 standard cubic meters at 80,000 pounds gross vehicle weight with mobile pipeline. The CNG can then be injected into a pipeline to serve additional demand in a more cost-effective manner than building additional transmission lines that might provide capacity needed for only short periods of time.
Measure the road route distance for trucking: Mobile pipeline can be successfully used to transport natural gas at distances upwards of 250 miles one way. Cost-effective operation requires at least one round trip per module every 24 hours.
Determine the module quantity (trailers and cylinders) required: Each mobile pipeline project requires multiple modules. A module will always be in the offload/decant process, and other module(s) will be either loading or in transit. The number of modules required for a project is a function of distance, load and capacity of the module. Type 4 composite modules offer significant capacity advantages over steel modules.
Ensure appropriate gas quality: All customers expect and must receive pipeline-quality gas.
Manage gas pressure and temperature: Natural gas is pressurized to 3,600 pounds per square inch gauge at the loading facility to obtain the density sufficient for cost-effective transportation. Specialized compression equipment is required to load and offload the modules. Regulating gas pressure and temperature is extremely important to ensure compatibility with other system components.
Assess your outsourcing or purchasing options: Mobile pipeline can be outsourced to service companies that specialize in sourcing natural gas on interstate pipelines, compression, transportation, delivery and decompression, and logistics and monitoring with end-to-end solutions. Other gas utilities may opt to purchase mobile pipeline modules with an eye on total cost of ownership.
Recently, a large natural gas utility company was faced with a difficult problem when a pipeline went offline and decreased supply during peak season. While some service was restored in the near term, it was several months before full capacity was restored. One of the methods that the utility company employed to meet gas supply obligations was mobile pipeline. Mobile pipeline equipment made between 16 to 20 trips per day and was able to move sufficient natural gas for more than 12,000 homes. This example shows the flexibility and ability for rapid deployment that will help a utility supply gas in a challenging situation.
An ongoing successful application of mobile pipeline is a paper mill in the Northwest that was able to switch to natural gas for operations, using natural gas that is trucked in daily. The company estimates that it saves $1.2 million in fuel costs and is reducing emissions by 17,000 tons of carbon dioxide per year, every year, thanks to mobile pipeline.
As natural gas demand shows no sign of abating, utilities nationwide are introducing innovative mobile pipeline solutions and utilizing the most up-to-date practices to help serve this need. As a result, mobile pipeline is providing safe, state-of-the-art technical solutions and agile deployment opportunities for this growing market.
Jon Smith is the global president of mobile pipeline for Hexagon and a retired naval officer with more than 21 years of service in the U.S. armed forces.